Fuse



Oct. 31A, 1933. N. N. oKUN 1,932,937

FUSE

Filed June 13, 1930 2 Sheets-Sheet l r l i v J/'g'g' ATITORNEY N. N. OKUN Oct. 31, 1933.

FUS E Filed June 13, 1930 2 Sheets-Sheet 2 '(Hml.; bIlm 1:1

Patented Oct. 31, 1933 UNITED STATES PrsNr oli-"F1os 3 Claims.

This invention relates to fuses for electric light circuits and is herein disclosed -embodied in a familiar type wherein the fusible link lies in a liber tube having metal caps on the ends.

In such fuses the link is replaceable, and when an electrician removes thefuse from the circuit the electrician often receives an electric shock, sometimes because there is no convenient place to seize the fuse and sometimesV because the poor connection between the link Lhe end terminals has caused an arc to form and burn away part of the fiber tube with the result that the metal parts slip and touch the fingers of the electrician giving him a shock.

According to the present invention these other difficulties are overcome in either of two ways or in both ways. One form of the invention provides an improved form of tube or grip which removes all temptation from the electrician to seize the ytube elsewhere, yet

and

is so formed as to conform to the rules of' theV nre underwriters. f

The other or additional form of the invention' provides an improved connection or improved seizing surfaces at the terminals to enable them to surely hold the fusible link, and yet be readily connected to` it. These connections may vary with the type oi link, which varies with the load of current the fuses are adapted to carry.

Other features and advantages will hereinafter appear.

In the accompanying drawings:

Figure 1 is a top view of a fuse embodying the present invention and adapted to carry to thirty amperes of current.

Figure 2 is an end View oi the same with the fuse in place.

Figure 3 is a similar View showing the link inserted and the parts before the link is made fast.

Figure 4 is an enlarged Section 4-4 of Figure 2.

Figure 5 is a perspective showing the link being inserted.

Figure 6 is a view ci the modiiied structure used in a fuse for carrying a heavier current" up to amperes7 parts being broken away.

Figure 7 is an end View of the Figure 8 is a Section on the line S-S of Figure 7.

Figure 9 is a face view ofthe fusible link.

Figure 10 is a face view of the parts which hold the link before inserting the link.

(Cl. 20G-131) to the casing any desired manner as by screws 22.

\ To enable any one to safely replace one yfuse or to hold the fuse for inserting c; the casing 20 is provided with a n gip 23 which maybe midway of the casonly thick enough to provide sufficient en th, thus it thinner than the casing 20, and can be inserted any where that the casing may inserted as part of the ruse. The grip 23 may be about half or less the length oi the casing between. its metal ends 21, and may be molded as part of the casing 2o or suitably made thereto. It is preferably made of insulating material, and for sureness of grip is hollowed out, at 2li, on each face so that it fits any normal thumb and forelinger. v

The usiblelink 25 is made'long enough to project at each end through an opening or slot 2S in a rotatable holding member 27 held by a screw 28 to the end or cover piece 29 of a metal end 2l, said screw entering a threaded central opening 30 of the member 27. The slot 26 enters at edge of the member 27 and runs far enough across the member 27 to easily accommodate the link 2li.V

The member 27 is shown as cut away at 3l, at the end oi the slot nearest the screw hole 30, thus providing an opening through 'which tne end oi the link 25 may be inserted, instead of requiring that it be inserted into the slot itself. When thus inserted the end of the link 25 may also project through an opening made by cutting To limit the throw or turn of the rotatable holding member 27 it is provided with a lug 35 which projects radially through a cut 36 in the periphery of the end 21.

Ihe lug lies almost against the end 37 of the cut 36 in inserting the link 25 in the slot 26, thus positioning the slot 26, and, if need be, serving as a finger piece for turning the member 27 to position the slot 26.

Upon turning the screw 28 the member 27 turns until the lug 35 strikes against the opposite end of the cut 36, and this end is usually further around than the edge 33, with the result that the member 27 adjacent the lug 35 lies largely under the cover piece 29 when the screw 28 is tight. The lug finally lies in the center plane or the finger grip 23.

Both ends of the fuse may be provided with identical parts, and the screws 28 may be provided wlth suitable devices as upset ends 39 so they can not be unscrewed and become loose and thus lost.

The fuse of Figure 6 is provided with a slightly modied form of ends 40 on its fiber casing 20 which may have the finger grip. The fusible link 25, in this form of the invention, is adapted to project through a slot 41 with closed ends and nearly in the center of the cover piece 42. The link is provided with forked ends 47 adapted, as they project through the slot 41, to be bent down around the stem 43 of a screw 44 by rotating a cover disk 45 around a pivot 46 near one edge of the cover piece 42. As the cover disk 45 swings around its pivot, it cams the projecting ends 47 down on to the upper surface of the cover piece 42.

The cover disk 45 is provided with a slot 48 adapted to admit the stem 43 of the screw 44 and just long enough to allow the disk 45 to swingi'iuntil it coincides with the cover piece 42. In that position the ends 47 of the link 25 have been cammed down flat and scraped clean. The screw 44 is then tightened and the fuse is ready for use. It should be noted that tightening of the Screw 44 causes its head 49 to turn on the disk 45 outside the slot so as to tend to draw the end of the slot 48 against its stem 43.

In Figure 11 is shown the fuse for heavy electric currents provided with an analagous case 20, which may also have a finger grip. Its metal end 50 is shown as carrying a contact lug 51 fast to or integral with it, as desired. The link 25 is shown as projecting through an almost radial slot 52 in the cover piece 53, so that the forked ends 47 may be bent down to lie on opposite sides of the stem 54 of a screw 55 threaded into the cover piece 53.

When thus bent, or partly bent down, a swiuging segment member 56 pivoted on a rivet at 57 near one edge of the cover piece 53 is swungover the forked ends 47 to cam them flat so that a slot 58 in it embraces the stern 55 and its flat edge 59 lies against the base of the contact lug 51. Then the screw 55 is tightened down on the segment 56, the parts being so arranged that the tightening of the screw tends to throw the segment against the lug 51.

Having thus described certain embodiments of the invention what I claim is:

1. In a fuse having a body, the combination with a fusible link, of a pair of relatively rotatable members, a slot in the rotatable member so located that the link projecting through the slot projects past a cutaway portion of the other member, and a screw threaded into the other member adapted to draw the members together and in so doing tending to draw the link under the body of the other member.

2. In a fuse having a. hollow non-conducting body, the combination with a fusible link and a rst end member having a slot through which an end of the link projects, of a second end member, the second end member having an eccentric edge and being rotatable on the other to bend over the projecting end of the link by the edge, and al screw passing through one of the members to draw the other against it.

3. In a fuse having a hollow non-conducting body, the combination with a fusible link and a first end member having a slot through which an end member having an eccentric edge and being rotatable on the other to bend over the projecting end of the link by the edge, and a screw passing through one of the members to draw the other against it and adapted to tend to continue turning the rotatable member in the same direction.

NATHANIEL N. OKUN. 

